Περίληψη:
Important land parameters such as soil texture, soil depth, topography,
parent material, and climatic conditions were studied in a semi-detailed
soil survey conducted in the island of Lesvos, and were related to the
vegetation performance and degree of erosion. Rainfall data indicated
that the island could be divided into two major climatic zones: a
semi-acid (western part) and a dry sub-humid (eastern part). A 45%
rainfall gradient has been recorded in the above two climatic zones. The
great reduction in rainfall combined with the higher evapotranspiraton
demands in the semi-arid zone has significantly affected vegetation
performance and degree of erosion in the area. Due to the general lack
of available water, the semi-arid part of the island is dominated by
poor marquis vegetation, while olive trees, oak and pine forests prevail
in the dry sub-humid part under similar topogaphical and
geomorphological conditions. Vegetation cover increases with increasing
rainfall and soil depth. Slope grade has a variable effect on soil
erosion in the various climatic zones. Erosion is decreasing with
increasing rainfall for the same slope classes. Severely eroded soils
prevail in the semi-arid zone with slopes greater than 12%, while
slightly to moderately eroded soils are found in the dry sub-humid zone
under similar slope classes. The highest rates of land degradation have
been measured in areas with soils formed on pyroclastic formations.
Areas with soils formed on basic igneous rocks, shale and lava are well
vegetated and protected from erosion under a broad range of slopes and
weather conditions. (C) 2000 Published by Elsevier Science B.V. All
rights reserved.
Συγγραφείς:
Kosmas, C
Danalatos, NG
Gerontidis, S
